In the manufacture of an electronic device, a silicon-containing film is etched by plasma. The silicon-containing film is made of a silicon-containing material such as silicon oxide or silicon nitride. The manufacture of a NAND type flash memory having a three-dimensional structure involves etching of a silicon-containing multilayered film having a plurality of silicon oxide films and a plurality of silicon nitride films alternately stacked on top of each other. The silicon-containing film is etched using a carbon-containing mask such as amorphous carbon mask. The mask has openings.
Patent Document 1 describes etching of the multilayered film. The multilayered film is etched by fluorine active species from the plasma generated using hydrofluorocarbon gas. A carbon-containing deposit that is formed on the mask protects the mask during the etching.
Patent Document 1: US Patent Application Publication No. 2013/0059450